Centralized traffic control system for railroads



p 1932- A. R. WHITEHORN 1,878,085

CENTRALIZED TRAFFIC CONTROL SYSTEM FOR RAILROADS Filed June 13. 1930 FIG. 1.

ATTORNEY Patented Sept. 20, 1932 units s'ra'rss PATENT orrics ARTHUR H. WHTTEHORN, OF ROCHESTER, NEW YORK, ASSIGNOR TO GENERAL RAIL- VJAY SIGNAL COMPANY, OF ROCHESTER, NEW YORK cnnrnamznn 'rnArr rc oonTnoL SYS EM FOR RAILROADS Application filed June .13, 1930; Serial neasoeze;

This invention relates to 'centralizedtraffic controlling systemsfor railroads, and more particularly to the provision of means for controlling a switch machine and four signals at a diverging route location over a single circuit and without the employment of selector apparatus. I 1

In accordancewith the present invention it is proposed to control-apparatus to five different conditions over-the same line circuit by employing current of one or another polarity and in;modulating or not modulating such current, therebyobtaining currents of four di'fierent characteristics, the fifth being' obtained by opening the line circuit under consideration. Q

Other objects, purposes and characteristic features of the present invention will in part be pointed out hereinafter and in "part be obvious from the, accompanying drawing. is

In describing the invention in detail reference may be had to the accompanying drawing in which Fig. 1 illustrates the central ofiice equipment within a dotted rectangle and conventionally shows the apparatus at a distant diverging route location, and

Fig. 2 shows a modified arrangement for supplying current to the neutral relays.

Strucrwa Referring to the drawing, the dotted rectangle T denotes a central oflice or tower, and the rails of the main track have been designated bythe reference character 10, and those of a passing siding or the diverging route are designated by the reference number 11. These track rails are divided by insulating-joints 12 in'the usual way to pro-.

vide the usual main track circuits and de' tector track circuits.

F ing'signal 1, as well as the switch machine SM, are controlled from the distant towerT through the mediumof the polar-neutral control relay Z and the neutral relays Z andZ These relaysZ, Z and Z are controlled from the battery B at the central office T through The side track 11 is connected to the main'track 10 by a track the me dium of the interrupter-I and the le 1 vers NHL and DL. Having now made brief references to each of the elements of the sys-' tem illustrated conventionally, it is believed expedient to consider the operation of the system to get a better understanding of the inter-relation of these devices and the functions intended to be carried out thereby.

Operation-Let us assume that there is a west bound train approaching on the main track, and that the operator wishes to clear the signal 1 to permit this train to pass into It is of the diverging route or side track. course necessary to operate the track switch S to the take-siding position, and this may be accomplished by operating the normalreverse lever NRL to the left hand position,

and since the signal to be cleared-is a west bound signal the operator will move the direction lever DL to its left hand position.-

With the levers NHL and DL in their left hand-position the following circuit for the control relay Z is closed :beginning at the mid-point of the battery B (this being the positive terminal of the left hand portion of the battery B), wire 15, common return wire p C, wire 16, primary winding of the relay Z, wire 17, lever DL, wires 18 and 19, lever NRL,

wire 20, to the negative terminaf of the bat tery B. The closure of this circuit operates the relay Z to its left hand position, thereby connecting the relay Z ina circuit including the secondary winding of the relay Z, and the wires 6, 7, 8' and 9, but since the current ap plied to the circuit is a steady uni-directional current no currentis induced in the secondary winding of the relay Z, and the relay Z re-;

mains deenergize d. Further, with the relay Z energizedtoward the left, the switch ma tacts and '38 of the relay Z." With the relay energized to the left and the relay Z deenergizedthe following circuit for'the sig nal 1? is closed :beginning at the terminal B of a suitable battery or other current source,

front contact 22 of the relay Z, wire 23, polar contact 24 of the relay Z assuming its left hand position, wire 25, back contact 26 of the thercontrolirelay Z is closedg-beginning at.

relay Z wire 27, mechanism of the signal 1 through suitable contacts controlled in accordance with traiiic conditions in advance,

and to the other terminal of the battery con taining the terminal B. The train in question may thereforeaccept thesignal; 1- if traflic conditions in advance arefavorable; and may pass into the diverging route.

Had the operator desired to have the train in question continue on the-main track, he Would have operated the lever NRL- to-the right and the lever DL to the left, thereb closing the same circuit heretofore traced: With the exception of including therighthand 53 part of the battery B instead of the left hand half. Under this condition the relay, Z would have been energized by current of; the uoppo site polarity and would havebeenloperated, to the. right, but the relay Z would havere-- mained deenergized, because the currentlfiows ing in the circuit under consideration, namely the circuit including Wires 9, '8, 46 ;and. 47%, WOHlClhElVG been a steady directioncurrentl. Under these conditions of the relay Zand Z the signal 1 would have been cleared, assum ing; favorable tr-aflic conditions exist. ahead,a through the following circuit :,beg-inning at V the terminal B, frontcontactQQ of therelay Z, wire 23;, polar" contact 24 wire,28, back contact-29 of the relay Z Wire 30, through the mechanism of signal 1 1 and through suitable, contacts- (not shown) controlled in -accordance with traffic conditions ahead; V

Letus now assumethattliere 'is an eastboundtrainonthe main track and.to,the.

rear ofrsignal 2, and that the operator :wishes thistrain toproceed on the main track- In order to do thisthe. operator mustcleantha signal 2, and; this may be; accomplished, by

moving the lever NRL toaitsright handdotted position and-Joy zrnoving the directionlever DL to its, right handdotted position.

WVith these levers N-El'gand D13 assuming the right hand position, the following circuinforthe'positive terminal of 'theterminal B, wire. 32,- lever NHL, wires; 19 and 83, winding ofthe interrupter; I, normally closed contactfid; of the/ interrupter 1, wire 35, leven-DL, wire-- 17 primary winding of therela-y Z wvires ,165,.

C and 15, and back to themid-point of-,-the battery B. The closure of the. circuit just traced allows current of positive polarity, to, flow through the-primary winding offthelre- I lay Z, but since this ,currentifiows through the interrupter I it will be {intermittently inter-1 rupted, thereby causing a pulsating cnrrenta of positive polarity to flow throughithefcircuitjusttraced. This pulsating current of,

positive polarityv operates the polar-contacts,

37, 38 and 24=to theright handiposition and effects closure of theneutral contacts 39, 4O and22, and sincethe pulsating,currentvpuh sates the flux in the core oftherelayZ a cure rent is induced inthesecondary windingfllr assumingits ri'ght hand'positio'n, Wire 28',-

front contact29 ofthe relay Z Wire 43, mechanism of the signal 2, through suitable contacts controlled in accordance with tratlic conditions in ,advance of the signal 2.

It is of course understood that the control relay Zidoes not only constitute a relay, but

also constitutes a transformer in that it-ine Let: us now assume, that; there is an1-east bound t-rainstanding on the; diverging route ofside track: 11, andthat-the operator Wishes this train to proceed ,in-yan eastwardly direct tion on to the main track 10.: Thismay bev accomplishedby moving the lever-NED to theilefthand orreverse position," and moving,

thedirection lever DL in its right-handor east bound position =With theseleverswin.

the last mentioned position,pulsating" cur rentofnegative-polarity: is applied to the control relay Z, through the,lasthtracedcircuit;

interrnpterl). therebyrausing themelay'Z; to be energized to itslefthand position vand permitting the voltage induced in thesecondary windingllof, relay. Z;to vcause alternating current to fiowin the windingv of the relayZE;

, Un der-theseconditions of, the; relays Z and for this relay Z (sa-id circuit including-{the Y Z the signal 2? is permitted to ;clear,.assum-. ing cleartrafficconditions exist ahead of :the. 1 signal- 2 through the. ,following; circuit beginning. atthe terminal B, frontcontactz22" of relay 1 Z, wire 23, polar cont-act 24, to, the

left, wire. 25 front contact 26 of the relay/Z wire;45 mechanism of the signal 2 and suit-.

able relay contacts rcontrolledlin.accordancea is with traffic conditions ahead\, g V Itis of course understood that theinven-H tion is equally as well. applicable tolight; signals as to, the; semaphore signals illustrated Also, if-desired,- ,a separatetransfornier may beused instead 10f using thei-relayiZ as. a trans-j."

former. I An arrangement of this! kind. has:- been-shown inaFi'gi2, Where thetransformer :TB has its primary winding includedr in series .with the relay Zf and has; its secondary winding connected in exactly: the same: wayr as ,the, secondary; winding e1; in-v. Fig-g l, gas is;

evident from the fact that like wires and contacts have been designated by like reference characters having distinctive exponents one. The apparatus of Fig. 1 has'been shown in its normal condition, in which all of the signals are held at stop and the switch machine assumes its last operated position, namely the main track position. The interrupterI is of the usual construction, including the normally closed biased Contact, which contact comprises a tuned armature, and which contact is opened upon the flow of current in the winding of the interrupter this opening of its contacts of course interrupts the flow of current allowing the contact to reclose, this operation is' repeated in rapid sequence, so that, a pulsating current-oi a frequency corresponding to the tuning of the armature oi. the'interrupter flows. 1

Having thus shown and described two specific embodiments of the present inventions it is desired to be understood that the particular embodiments selected have been selected for the purpose of exemplifying the invention, rather than illustrating its scope, or the exact construction preferably used in practicing the invention, and that various changes, modifications and additions may be made to the arrangement illustrated without departing from the spirit of the invention or its scope, except as demanded by the scope of the appended claims.

What I claim as new is a 1. In combination, a line circuit, a double winding relay having one of its windings'included in said line circuit, a second relay included in circuit with the other winding of said double winding relay, and means for energizing said line circuit with either continuous or pulsating unidirectional current.

2. In combination, a line circuit, a double winding polar relay having one of itswindings included in said line circuit, a second re-' lay included in circuit with the other winding of said double winding relay, and means for energizing said line circuit with continuous current of one polarity or the other or pulsating uni-directional current of one polarity or the other.

3. In combination, a line circuit, a double winding polar relay having one of its windings included in said line circuit, a second relay included in circuit with the other winding of said double winding relay, and means,

for including a battery of one polarity or the other in said circuit and including an interrupter in said circuit. 7

4. In combination, a line circuit, a double winding relay having one of its windings included in said line circuit, a second relay included in circuit with the other winding of said double winding relay, a contact ofsaid double winding relay included in the circuit of said second relay, and means for energizof said double-winding relay, a polar contact 7 of said double winding relay included in the circuit of said second relay, and means for energizing said line circuit by direct current of one or the other polarity or by pulsating current of a. particular polarity.

6. In co'mbination,-a line circuit, a double 1 winding polar relay having one of its windings included in said line circuit, a second relay included in circuit. with the other winding of said'double winding relay,.means for energizing said line circuit with continuous current of one polarity orv the other or pulsating uni-directional current of one polarity orthe other, a track switch of a railway systern, a signalfor governing the movement of traiiic on the-main track and on the diverging V route for each direction of train-movement, and circuits for governing said signals in accordance with the direction a train shall move controlled by said second relay and for governing said signals to indicate whether such train shall move on the main track or on the pliverging route, controlled by said polar re- 7. In combination, a line circuit, a double winding polar relay having one of its windings included in said line circuit, a second relay included in circuit with the other winding of said double winding relay, means for energizingsaid line circuit with continuous current of one polarity or the other 'or pule sating uni-directional current of one polarity or the other, a track switch at a diverging route point, a. switch'machine for operating said track switch, means for controlling said track switch by said polar relay,an d means for controlling the direction indication of said signals in accordance with theposition of saidsecond relay.

8. In combination, a line circuit, a polar relay included in said line circuit, a second relay inductively coupled to said line circuit, means for energizing said line circuit with continuous current of one polarity or the other or pulsating uni-directional current of one polarity or the other, and railway trafi'ic pontrolling apparatus controlled by said reays. I n 9. In combination, a line circuit, a polar relay having its winding included in said line circuit, a second relay inductively coupled to said line circuit, and means for including a batteryof one polarity or the otherin said circuit and including an interrupter in said circuit. Y 1

10. In combination, a line circuit, a relay having its winding included in said line circuit, a second relay inductively coupled with said line circuit, a contact of "said first relay included in the circuit of said second relay, and means for energizing said line circuit by continuous direct current or by pulsating current. 1

11. In combination, a line circuit, a polar relay having its winding included in said line circuit, a second relay inductively. coupled with said line circuit, a polar contact of said first relay included in the circuit of said sec 0nd relay, and means for energizing said line circuit by direct current of oneor the other polarity or by pulsating current of a'particular polarity.

12. In combination, a line circuit, a polar relay having its Winding included in said line circuit, a second relay inductively coupled to said line circuit, means for energizing said line circuit with continuous current of one polarity or the other or pulsating uni-directionalcurrent of one polarity or the other, a track switch of arailway system, asignal for governing the movement of traffic on the main track and onthe diverging route for each direction" of train movement, and circuits for governing said signals in accordance with the direction atrain shall move controlled by said second relay and for governing said signals to indicate whether such train shall move on the main track or on the diverging route controlled by said polar relay. r

18. In combination, a line circuit, a polar relay having its winding included in said line circuit, a second relay inductively i coupled to said line circuit, means for energrz1ng'sa1d l-lne 'clrcult with continuous current of one polarity or the other or pulsating uni-directional cur-rent, of one polarity or the other, a track switch at a diverging route point, a switch machine for operating said track switch, means for controlling said track switch by said polar relay,.a-nd means for controllingthe direction indication of said signals in accordance with the position 1 of said second relay.

In testimony whereof I afiiX my signature.

ARTHUR RiWHITEHORN. 

